[ursman]

REALISTICALLY ... I would keep your 4.2L if it's not blowing smoke to bad from rings/valves, for budget reasons. A Weber is good so long as you aren't in a smog state (I don't know what Canada's smog laws are). If you don't have to worry about smog, then remove the AIR tubes/pump as applicable along with extraneous vac lines. For max carb power, i'd go with the Weber 38 as it has the largest venturis/secondaries. I went with the Weber for a few years but got tired of having to yank it all off when it came time for emissions testing. I saved up and got the Howell TBI which is probably the biggest single improvement you can do to any 4.2L. The driveability and power are unbeatable. I also went with Terry's advice on the TFI upgrade. If you're on a budget (like most of us!) This is a good step in the right direction. Also, any good muffler shop would be able to fab up some custom exhaust for a good canuck price!